docs: def _getgroup(string, depth):
      """
      Get a group from the string, where group is a list of all the comma
      separated substrings up to the next '}' char or the brace enclosed substring
      if there is no comma
      """
      out, comma = [], False
      while string:
          items, string = _getitem(string, depth)
  
          if not string:
              break
          out += items
  
          if string[0] == '}':
              if comma:
                  return out, string[1:]
              return ['{' + a + '}' for a in out], string[1:]
  
          if string[0] == ',':
              comma, string = True, string[1:]
  
      return None